<html>
    <head></head>
    <body>
        <div>左右布局</div>
        <div class="container" id="inline">
            <div class="sectionA" id="left">

            </div>
            <div class="sectionB" id="right">

            </div>
        </div>
        <div class="container" id="column">
            <div class="sectionA" id="top">

            </div>
            <div class="sectionB" id="bottom">

            </div>
        </div>
        <div class="container" id="centerWrapper">
            <div class="smallContainer" id="center">

            </div>
        </div>
     <style>
        body>*{
            margin:10px;
        }
        .container{
            width: 640px;
            height: 640px;
            background-color: bisque;
            position: relative;
        }
        .sectionA{
            background-color:chartreuse;
        }
        .sectionB{
            background-color: crimson;
        }
        .smallContainer{
            background-color: gold;
            width: 32px;
            height: 32px;
        }
        #inline{
            display: inline-flex;
        }
        #left{
            flex: 1;
            height: 100%;
        }
        #right{
            flex:1;
            height: 100%;
        }
        #column{
            display: flex;
            flex-direction: column;
        }
        #top{
            flex:1;
            width: 100%;
        }
        #bottom{
            flex: 1;
            width: 100%;
        }
        #centerWrapper{
            display: flex;
            justify-content: center;
            align-items: center;
        }
    </style>   
    </body>
    
</html>